Vacuum relay for radio frequency signals



ug. 15, 1967 v. E. DE LUCIA VACUUM RELAY FOR RADIO FREQUENCY STGNALS Filed April 22, 1966 United States Patent Gti t3,336,546 Patented Aug. 15, 1967 ice 3,336,546 VACUUM RELAY EUR RADIO FREQUENCY SIGNALS Victor E. De Lucia, 927 Euclid Ave., Santa Monica, Calif. 90403 Filed Apr. 22, 1966, Ser. No. 544,480 4 Claims. (Cl. 335-154) The present invention relates to electric relay switches of the type having their operating components enclosed in an evaculated envelope; and it relates more particularly to an improved vacuum relay which is particularly adapted to switch radio frequency signals, but which has general utility.

The particular relay `to be described herein includes movable and fixed contacts, as well .as a movable magnetic armature and magnetic pole pieces, .all enclosed in an evacuated envelope. The envelope is preferably formed of a material, such as ceramic, which provides a low dielectric loss factor to high `radio frequency currents.

An object of the invention is to provide such an improved vacuum relay which is capable, for example, of switching high voltage, high frequency signals at a relatively high rate and for prolonged periods of time without deterioration of its switching components.

However, as mentioned above, it will become evident as the description proceeds, that the improved relay of the present invention has general application.

Another object of the invention is to provide such an improved vacuum relay which exhibits high magnetic eiciency so as to achieve a relatively high pull-in force of its armature with relatively low amperesturns in it-s energizing circuit.

A further object of the invention is to provide such an improved vacuum relay which is relatively simple in its construction and which may be conveniently adjusted during fabrication to be established at desired operating characteristics.

Other objects and advantages of the invention will become apparent from a consideration of the following description, when the description is taken in conjunction with rthe accompanying drawing, in which:

FIGURE 1 is a perspective view of a relay which may be constructed in accordance with the concepts of the present invention;

FIGURE 2 is an exploded view of the relay of FIG- URE 1, illustrating in perspective the various components which make up the relay;

FIGURE 3 is a side sectional View of the relay of FIG- URE 1, taken essentially along the line 3 3 of FIGURE 1, and revealing the internal operating components of the relay;

FIGURE 4 is a fragmentary perspective view of various operating components of the relay, and illustrating in further detail the structure of the components; and

FIGURE 5 is a fragmentary side sectional view showing details of a movable contact assembly which is included in the relay.

The improved vacuum `relay of the present invention, as illustrated in the drawings, includes for example a tubularshaped envelope 10. The envelope may be composed of ceramic, or other low loss material.

The envelope 10 has a cup-shaped lconfiguration in the illustrated embodiment, so as to have a closed top and an open bottom in the views of FIGURES 1, 2 `and 3, for example. The illustrated embodiment is a single-pole double-throw relay, and for that reason, three electrodes in Ithe form of copper rods 12, 14 and 16 extend into the envelope 10 through its closed top. It will be appreciated, of course, that the concepts of the present invention are not limited to single-pole double-throw relays.

An annular pole piece member 18 composed of iron, or other suitable magnetic material, is mounted on the envelope 10 by means of a ring 20. The annular member 18 serves to enclose the open end of the envelope 10. The ring 20 is formed of Kovar, or .other suitable material. The ring 20 is sealed to the ceramic envelope 10, and the member 18 is attached to the ring by silver brazing, or the like.

A tubular member 22 is welded, or otherwise affixed, to the outer face of the member 18 in position to surround the central opening therein. The tubular member 22 is composed of Monel metal, or other suitable non-magnetic material.

An elongated cylindrica1-shaped core member 24 is welded, or otherwise secured to the end of .the tubular member 22 in coaxial relationship with the tubular member. The elongated core member 24 is composed of iron or other suitable magnetic material.

A central passageway is provided through the `core member 24 along its longitudinal axis, for example, in communication with the interior of the tubular member '22 and with the interior of the envelope 10. A Itube 26 is disposed in the passageway, and this tube protrudes out through the end of the member 24.

The tube 26 provides for a convenient means for evacuating or gas lilling the envelope 10 `and for outgassing the assembly. After the evacuation is completed, the lower end of the tube 26 is sealed, as shown in FIG- URES 2 and 3.

The provision of the evacuating tube 26 in the lower portion of the assembly, rather than in the envelope 10 itself (as is the usual prior art practice), is advantageous. This is because the provision of an additional metallic tube through the casing 10 lowers the breakdown voltage with respect to the electrodes 12., 14 and 16. Also, in the event of a reject, there is no need to discard the relatively expensive ceramic envelope assembly.

The energizing coil 30 for the assembly is supported on a disc-like ba-se 32, and energizing terminals 34 and 36 for the coil extend through the base. The coil is supported within a housing 40 which is composed of iron or other suitable magnetic material. The housing 40 has a tubular conguration, and it includes an integral annular ange at its upper end.

The housing 40 may be threaded, `as shown, so as to provide a mounting means for the relay. The coil 30 is inserted in the housing 41) so as to surround the core member 24, as best shown in FIGURE 3. The assembly is held in place by a nut 42 which is threaded to a threaded portion at the end of the core member 24. The tube 26 extends `down through the end of the core 24, and is protected, for example, by means of a cap 46.

An armature 50 is pivotally mounted on the upper surface of the pole piece member 18, and the armature includes a tubular skirt portion which extends through the opening in the member 18 and down into a well which is formed by the tubular member 22 and the core member 24.

A spring 52 is positioned in the Well, and the spring bears against the underside of the armature, so that it is normally biased to the up position, as best shown in FIGURE 3. A hook-shaped member 54 is welded, or otherwise aiiixed to the upper face of the armature 50.

The electrodes 12 and 16 serve as the Xed contacts of the relay, and the electrode 14 supports a movable contact 60. The movable Contact 60 is a resilient strip composed, for example, of tungsten. It is rivetted to the post 14 as at 62.

When the movable contact 60 is in one position, it engages a xed contact 66 which, for example, is staked to the lower end yof the electrode 12. On the other hand, when the contact 60 is in a second position it engages a xed contact 68 which is staked to the lower end of the electrode 16.

A yoke 70 is mounted on the xed contact 60 as by rivetting or welding, and it extends transversely across the fixed contact at a point intermediate its ends, as best shown in FIGURE 4. A sapphire rod 72 is supported in the yoke 70. A pair of metallic eyelets 74 and 76 are pressitted to the ends of the sapphire rod, and these eyelets are crimped into holes in the yoke 70.

The movable contact 60 may be composed, for example, of molybdenum. As mentioned above, the rod or pin 72 may be composed of polished sapphire, or other appropriate insulating material may be used. The eyelets may be crimped to the yoke 70, as mentioned above, or spot welded, or affixed thereto in any other appropriate manner.

The hook-like member 54 is hooked to the sapphire rod 72 when the relay is assembled. The spring 52 causes the assembly normally to be biased to the up position shown in FIGURE 3 in which the movable contact 60 engages the fixed contact 66. However, when the relay is energized, the armature 50 is drawn down into the well formed by the tube 22, and the movable contact is moved down into engagement with the fixed contact 68.

It will be appreciated that the magnetic circuit of the relay is extremely efficient in that opposing poles are created by the energizing coil 30 at the pole piece member 18 and at the upper end of the core member 24, so that an extremely strong pull-in eld is provided for the armature 50. The pull-in and drop-out voltages of the relay can be adjusted, by the provision of non-magnetic washers of different thickness at the bottom of the well formed by the tubular member 22.

The coil housing 40 for activating the relay is not an integral part of the relay. This assembly is mounted on the relay separately after the relay is evacuated or gas filled, and is held in place by the nut 42. The advantage of this scheme is that coils of different ampere-turns can be installed to accommodate different spring pressures. It has also been found that if the coil housing 40 is made part of the relay structure that severe hydrogen absorption takes place in the metallic components of the relay during the subsequent electroplating of the body (for corrosion resistance purposes) which hinders its ability to withstand high voltage during life, due to the hydrogen absorption in the bulb of the relay which destroys the high vacuum. This deleterious effect is eliminated by making the coil housing 40 separate from the relay body. By this means, the relay coil housing 40 can be electroplated and applied to the relay assembly after evacuation.

By designing the relay without the coil housing 40 provides that better out-gassing can be accomplished during the evacuation cycle due to the lower mass of lmetal present. In addition, the contact assembly and the magnetic assembly of the relay are engaged and made operable without the need of extensive adjustments or the necessity to see inside the unit.

While a particular embodiment of the invention has been described, modifications may be made. It is intended in the claims to cover all modifications which come within the spirit and scope of the invention.

What is claimed is:

1. In a vacuum relay which includes an envelope, the

combination of: a wall member of magnetic material 6 aixed to said envelope and enclosing one end thereof, said wall member having an opening therein; a tubular member of non-magnetic material affixed to the outer surface of said wall member in position surrounding said opening therein and extending outwardly from said wall member; an elongated member of magnetic material affixed to the end of said tubular member remote from said wall member and disposed in coaxial relationship with said tubular member; and an armature of magnetic material pivotally mounted on the inner surface of said wall member and positioned within said envelope to have a portion thereof drawn through said opening in said wall member and down into said tubular member.

2. In a vacuum relay which includes an envelope, the combination of: a wall member of magnetic material affixed to said envelope and enclosing one end thereof, said wall member having an opening therein; a tubular member of non-magnetic material affixed to the outer surface of said wall member in position surrounding said opening therein and extending outwardly from said Wall member; an elongated member of magnetic material afxed to the end of said tubular member remote from said wall member and disposed in coaxial relationship with said tubular member; an evacuating tube for said envelope extending longitudinally through said elongated member and communicating with the interior of said tubular member; and an armature of magnetic ymaterial mounted in said envelope in position to have -a portion thereof drawn through said opening in said wall member and down into said tubular member.

3. In a vacuum relay which includes an envelope, the combination of: a wall member of magnetic material af- :fixed to said envelope and enclosing one end thereof, said wall member having an opening therein; a tubular member of non-magnetic material amxed to the outer surface of said wall member in position surrounding said opening therein and extending outwardly from said wall member; an elongated member of magnetic material Iaffixed to the end of said tubular member remote from said wall member and disposed in coaxial relationship with said tubular member; an armature of magnetic material mounted in said envelope in position to have a portion thereof drawn through said opening in said wall member land down into said tubular member; an elongated movable contact mounted within said envelope, a transverse yoke affixed to said movable contact; an insulating rod supporting said yoke; and a hook-like member mounted on said armature and engaging said insulating rod to cause said movable contact to move with movement of said armature.

4. The combination defined in claim 3 and which includes a pair of metallic mounting eyelets in press fit with the respective ends of said insulating rod and affixed to said yoke.

References Cited UNITED STATES PATENTS 1,195,472 8/1916 Houchin 335-171 X 1,421,740 7/1922 Stevens 20G-169 X 1,503,321 7/1924 Hartel 20G-169 2,255,638 9/1941 Armstrong 335-154 X 3,035,139 5/1962 Lindsay 335-154 3,079,481 2/1963 Jennings 200k-144 3,219,781 ll/1965 Miller et al. 335-131 X BERNARD A. GILHEANY, Primary Examiner.

I. lI. BAKER, R. N. ENVALL, IR., Assistant Examiners. 

1. IN A VACUUM RELAY WHICH INCLUDES AN ENVELOPE, THE COMBINATION OF; A WALL MEMBER OF MAGNETIC MATERIAL AFFIXED TO SAID ENVELOPE AND ENCLOSING ONE END THEREOF, SAID WALL MEMBER HAVING AN OPENING THEREIN; A TUBULAR MEMBER OF NON-MAGNETIC MATERIAL AFFIXED TO THE OUTER SURFACE OF SAID WALL MEMBER IN POSITION SURROUNDING SAID OPENING THEREIN AND EXTENDING UPWARDLY FROM SAID WALL MEMBER; AN ELONGATED MEMBER OF MAGNETIC MATERIAL AFFIXED TO THE END OF SAID TUBULAR MEMBER REMOTE FROM SAID WALL MEMBER AND DISPOSED IN COAXIAL RELATIONSHIP WITH SAID TUBULAR MEMBER; AND AN ARMATURE OF MAGNETIC MATERIAL PIVOTALLY MOUNTED ON THE INNER SURFACE OF SAID WALL MEMBER AND POSITIONED WITHIN SAID ENVELOPE TO HAVE A PORTION THEREOF DRAWM THROUGH SAID OPENING IN SAID WALL MEMBER AND DOWN INTO SAID TUBULAR MEMBER. 